High cell counts in granulocyte concentrates especially granulocyte colony-stimulating factor (G-CSF) mobilized granulocytes are detrimental to concentrate storage. An eight-fold dilution with autologous plasma improves storage, but this method is impractical. Granulocytes collected from donors given dexamethasone (8 mg PO) and/or G-CSF (5 mg SQ) were diluted eight-fold in plasma, cell culture media: X-Vivo 10, Dulbecco?s Modified Eagle?s Medium (DMEM), Iscoves Modified Dulbecco?s Medium (IMDM) or infusible solutions: Plasma-Lyte A, Normosol R, and lactated Ringer?s, supplemented with 1 percent human serum albumin and 50 mM histidine (LRAH) or Plasma-Lyte A supplemented with 50 mm histidine or 25 mM HEPES buffer plus 1 percent human serum albumin. The granulocytes were stored for 48 hours at room temperature. White blood cell (WBC) counts, WBC viability, and pH were measured after approximately 2 hours, 24 hours, and 48 hours of storage. Cell counts, viability, and pH were maintained after 2 hours, 24 hours, and 48 hours in cells stored in the three cell culture media. The pH and cell counts fell after 24 hours and 48 hours in granulocyte concentrates stored in Plasma-Lyte A and Normosol. The cell counts of concentrates diluted in LRAH were stable for 48 hours. The pH fell in cells diluted in LRAH, but was greater than granulocyte concentrates diluted in Plasma-Lyte A or Normosol. The pH of granulocyte concentrates diluted with Plasma-Lyte A plus histidine or HEPES was better maintained than the pH of granulocytes diluted in Plasma-Lyte A alone. Cell counts were better maintained in granulocyte concentrates diluted in Plasma-Lyte A plus albumin and histidine or HEPES than those in diluted with Plasma-Lyte A alone or in Plasma-Lyte A plus histidine or HEPES. Infusible solutions are not buffered adequately, but infusible solutions such as lactacted Ringer?s solution or Plasma-Lyte A supplemented with buffers and albumin hold promise as an effective solution for granulocyte storage.